<?php

namespace plugin\struct\meta;

/**
 * Manage dynamic parameters for aggregations
 *
 * @package plugin\struct\meta
 */
class SearchConfigParameters {

    /** @var string parameter name to pass filters */
    public static $PARAM_FILTER = 'flt';
    /** @var string parameter name to pass offset */
    public static $PARAM_OFFSET = 'ofs';
    /** @var string parameter name to pass srt */
    public static $PARAM_SORT = 'srt';

    /** @var SearchConfig */
    protected $searchConfig;

    /** @var null|array */
    protected $sort = null;
    /** @var int */
    protected $offset = 0;
    /** @var  array */
    protected $filters = array();

    /**
     * Initializes the dynamic parameters from $INPUT
     *
     * @param SearchConfig $searchConfig
     */
    public function __construct(SearchConfig $searchConfig) {
        global $INPUT;
        $this->searchConfig = $searchConfig;
        /** @var \helper_plugin_struct_config $confHlp */
        $confHlp = plugin_load('helper','struct_config');

        if($INPUT->has(self::$PARAM_SORT)) {
            list($colname, $sort) = $confHlp->parseSort($INPUT->str(self::$PARAM_SORT));
            $this->setSort($colname, $sort === 'ASC');
        }

        if($INPUT->has(self::$PARAM_FILTER)) {
            foreach($INPUT->arr(self::$PARAM_FILTER) as $colcomp => $filter) {
                list($colname, $comp, $value,) = $confHlp->parseFilterLine('AND', $colcomp . $filter);
                $this->addFilter($colname, $comp, $value);
            }
        }

        if($INPUT->has(self::$PARAM_OFFSET)) {
            $this->setOffset($INPUT->int(self::$PARAM_OFFSET));
        }
    }

    /**
     * Returns the full qualified name for a given column
     *
     * @param string|Column $column
     * @return bool|string
     */
    protected function resolveColumn($column) {
        if(!is_a($column, '\plugin\struct\meta\Column')) {
            $column = $this->searchConfig->findColumn($column);
            if(!$column) return false;
        }
        /** @var Column $column */
        return $column->getFullQualifiedLabel();
    }

    /**
     * Sets the sorting column
     *
     * @param string|Column $column
     * @param bool $asc
     */
    public function setSort($column, $asc = true) {
        $column = $this->resolveColumn($column);
        if(!$column) return;
        $this->sort = array($column, $asc);
    }

    /**
     * Remove the sorting column
     */
    public function removeSort() {
        $this->sort = null;
    }

    /**
     * Set the offset
     *
     * @param int $offset
     */
    public function setOffset($offset) {
        $this->offset = $offset;
    }

    /**
     * Removes the offset
     */
    public function removeOffset() {
        $this->offset = 0;
    }

    /**
     * Adds another filter
     *
     * When there is a filter for that column already, the new filter overwrites it. Setting a
     * blank value is the same as calling @see removeFilter()
     *
     * @param string|Column $column
     * @param string $comp the comparator
     * @param string $value the value to compare against
     */
    public function addFilter($column, $comp, $value) {
        $column = $this->resolveColumn($column);
        if(!$column) return;

        if(trim($value) === '') {
            $this->removeFilter($column);
        } else {
            $this->filters[$column] = array($comp, $value);
        }
    }

    /**
     * Removes the filter for the given column
     *
     * @param $column
     */
    public function removeFilter($column) {
        $column = $this->resolveColumn($column);
        if(!$column) return;
        if(isset($this->filters[$column])) unset($this->filters[$column]);
    }

    /**
     * Remove all filter
     */
    public function clearFilters() {
        $this->filters = array();
    }

    /**
     * @return array the current filters
     */
    public function getFilters() {
        return $this->filters;
    }

    /**
     * Get the current parameters in a form that can be used to create URLs
     */
    public function getURLParameters() {
        $params = array();
        if($this->offset) {
            $params[self::$PARAM_OFFSET] = $this->offset;
        }

        if($this->sort) {
            list($column, $asc) = $this->sort;
            if(!$asc) $column = "^$column";
            $params[self::$PARAM_SORT] = $column;
        }

        if($this->filters) {
            $params[self::$PARAM_FILTER] = array();
            foreach($this->filters as $column => $filter) {
                list($comp, $value) = $filter;
                $params[self::$PARAM_FILTER][$column . $comp] = $value;
            }
        }

        return $params;
    }

    /**
     * Updates the given config array with the values currently set
     *
     * This should only be called once at the initialization
     *
     * @param array $config
     * @return array
     */
    public function updateConfig($config) {
        if($this->offset) {
            $config['offset'] = $this->offset;
        }

        if($this->sort) {
            list($column, $asc) = $this->sort;
            $config['sort'] = array(
                array($column, $asc)
            );
        }

        if($this->filters) {
            if(empty($config['filter'])) $config['filter'] = array();
            foreach($this->filters as $column => $filter) {
                list($comp, $value) = $filter;
                $config['filter'][] = array($column, $comp, $value, 'AND');
            }
        }

        return $config;
    }

}